This image made from a Thursday, April 13, 2017 video released by the U.S. Department of Defense shows a GBU-43/B Massive Ordnance Air Blast bomb strike on an Islamic State militant cave and tunnel systems in the Achin district of the Nangarhar Province in eastern Afghanistan. U.S. forces in Afghanistan on Thursday struck an Islamic State tunnel complex in eastern Afghanistan with the largest non-nuclear weapon every used in combat by the U.S. military, Pentagon officials said.